Dishware Unit and Method for Sealing Partially Prepared Meals

ABSTRACT

The invention relates to a dishware unit for packaging, transporting, and/or serving meals and to a method for sealing at least partially prepared meals, comprising a body which is covered with a film. An adhesive is introduced between the film and the body in an adhesive region in order to seal the dishware unit. The film and the dishware unit have such a degree of surface tension that the adhesive at least largely adheres to the film when the film is removed, wherein the surface tension in the adhesive region in the film is greater than the surface tension in the adhesive region in the body.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

This patent application claims priority from PCT Patent Application No. PCT/EP2019/000015 filed Jan. 16, 2019, which claims priority from German Patent Application No. DE 102018000407.5 filed Jan. 19, 2018. Each of these patent applications are herein incorporated by reference in their entirety.

OBJECT OF THE INVENTION

The present invention relates to a tray unit, and particularly to a dish, for the packaging, transport, and/or consumption of foods, wherein the tray unit has a body covered with a film and wherein an adhesive (an adhering hot-melt adhesive) for sealing the tray unit is present between the film and the body.

BACKGROUND OF THE INVENTION

Tray units and methods for sealing tray units with foods arranged thereon are known in the state of the art. For example, document DE 691 00 484 T2 discloses a method to provide a container with an edge made of a material that can be hot formed and weld this edge to the closure cover. Document EP 2 886 329 A1 discloses a packaging with a bowl and a cover film. The bowl has a polyester layer adjacent to the cover sheet and the cover sheet has a sealing layer of a polymeric base substance adjacent to the bowl. In this regard, the cover film can be subjected to corona treatment.

The objective of the present invention is to provide a tray unit and a method for sealing, whereby high-quality foods, as well as top-quality foods, and foods that are at least partially prepared at least in part can be housed, preserved, and transported, and/or consumed. For example, the foods arranged on the tray unit can be components of a part of a meal.

This objective is achieved by means of a tray unit with the features of claim 1 and by means of a method with the features of claim 19. Preferred improvements of the invention are object of the dependent claims. Additional advantages and features of the invention can be inferred from the general description and the description of the embodiments.

A tray unit according to the invention is particularly configured as a dish and is used for the packaging, transport, and/or consumption of foods. Furthermore, the tray unit can also be used for preparing and/or elaborating foods or components, for example, of a part of a meal. The tray unit comprises a particularly temperature-resistant body. The body is covered with a film. An adhesive for sealing the tray unit is present between the film and the body in an adhesive region. In this regard, the film and the tray unit (particularly the dish) have a surface tension such that the adhesive adheres at least predominantly on the film upon removing the film. For this purpose, the adhesive used must have a specific adhesion. In this regard, the surface tension of the lower side of the film is set at least in the adhesive region in the film such that the surface tension in the film is greater than the surface tension in the adhesive region in the body. In specific configurations, the surface tension on the lower side of the film is preferably greater than 42 mN/m (also dyn/cm) and the surface tension in the adhesive region of the tray unit is preferably 41 mN/m or less, for example.

The expression “the adhesive adheres at least predominantly on the film upon removing the film” from the tray unit must be understood in the sense of the present invention to mean that at least 90% or at least 95% of the mass of the adhesive remains adhered to the film upon removing the film. Particularly, at least 99% of the mass of the adhesive remains on the film upon removing the film. These mentioned numbers are valid for the general case. A higher percentage of the adhesive remaining on the tray unit, for example, in one out of 20, 50, or 100 cases, cannot be ruled out. Nevertheless, upon removing the film, the adhesive peels off the tray unit evenly for the most part or almost completely, such that additional cleaning of the adhesive region of the tray unit is not required before consuming the pre-prepared foods.

The tray unit according to the invention has many advantages. A considerable advantage consists of the ability to finish preparing the foods directly or to make the foods directly available for consumption when an additional preparation is not required after removing the film from the tray unit. The film for sealing the tray unit can thereby be removed without special precautionary measures or without any particular effort, without unsightly residues of the adhesive remaining on the tray unit. A visually pleasing general impression is also thereby achieved.

In a preferred improvement, the body has at least one base section and at least one edge section. In a particularly preferable manner, the adhesive region is configured in the edge section. Particularly, the base section is used for housing at least one food. It is also possible for not only one base section but rather several base sections to be envisaged or configured in the body. For example, a second base section or an independent base section which is used for housing an independent container or an independent bowl such as, for example, a small dispenser for sauce or for other foods or ingredients, can be envisaged. Preferably, at least one edge section runs around the body and thereby completely surrounds a central region of the body. Furthermore, it is particularly preferable for the adhesive region or at least one adhesive region to extend completely around the body. In this regard, preferably at least one base section is entirely surrounded by a continuous adhesive region, such that a complete and secure sealing of the foods in the tray unit can be assured. The adhesive should form a closed ring after being applied on the body given that, otherwise, a mixture of protective gases added below the film may leak out, for example.

Preferably, the edge section is raised at least in the adhesive region with respect to the base section. An edge section of this type facilitates gripping the tray unit or the dish, as well as placing it on a table or in a cooking appliance. A raised edge section in the adhesive region can also facilitate the application of adhesive in the adhesive region when the adhesive is applied by means of rollers or the like, for example.

It is possible and preferred that the body presents an application surface for the adhesive provided by the adhesive region. An application surface of this type can be configured, for example, in a raised area extending along the adhesive region. The application surface preferably has defined dimensions and may particularly have a width of between 1.5 mm and 10 mm, and particularly between about 2 and 6 mm. A width of about 3 or 4 mm (+/−2 mm) is possible, for example.

Preferably, the body has in total a width of between 10 cm and 25 cm and a length of between 20 cm and 38 cm. In preferred configurations, it can have a width of between 15 cm and 20 cm and a length of between 25 cm and 35 cm. Particularly, the dimensions of the body are adapted to the dimensions of the cooking appliance, and in this regard, particularly to the cooking space of the cooking appliance, such that the cooking space can house a predetermined number of tray units without large intermediate spaces (of more than 2 cm or 3 cm) being produced and thereby wasting space for housing the tray units. With a cooking appliance having dimensions for housing the products to be cooked that measure 42.5 cm wide and 35.5 cm long, 2 tray units can preferably be placed side by side on the holder for holding the products to be cooked, wherein on one hand, there will still be enough space for handling the tray units, and on the other, not much intermediate space will be wasted. Generally, the measurements of the tray unit should be chosen such that when placing the highest possible number of tray units on a holder for holding the products to be cooked at least 10% or 20% and no more than 30% or 40% of the holder for holding the products to be cooked remain free.

In a particularly preferable manner, the body is made at least partially, and particularly at least essentially or completely, of a ceramic-type material. In particularly preferred improvements, the body is made at least partially or essentially or completely of magnesium oxide. Tray units made of a ceramic-type material and/or magnesium oxide can be produced in many different forms and are suitable for the preparation and consumption of foods due to their nature. Magnesium oxide-based tray units are more lightweight than conventional porcelain while still being equally impact resistant. Such tray units are therefore particularly suitable for regular as well as professional use, for transport, and for multiple use.

In a particularly preferable manner, the body is essentially designed to be rectangular or polygonal. In this regard, preferably, it is possible for at least one corner to have a rounded design. Rectangular or essentially rectangular configurations allow a high packing density.

The film for covering (and sealing) the foods in the tray unit is preferably made of a plastic material and has a thickness of between 50 μm and 150 μm. In a particularly preferable manner, the film is made at least partially, or in particular, completely of a material such as polyethylene terephthalate (PET).

Preferably, the lower side of the film is attached to the body of the tray unit. In a particularly preferable manner, the surface tension on the lower side of the film is modified by means of at least one surface treatment. It is also possible for the upper side of the film to be subjected to a surface treatment or the like. Preferably, at least a part of the lower side of the film is surface treated by means of a corona treatment. In the corona treatment, the film is generally exposed to a high-voltage electric discharge. If only one side of the film is treated, then the film can be supported on a polished roller, for example, whereas on the other side of the film an electrode is arranged. For the surface treatment, a high-frequency generator with an AC voltage between about 10 and 20 kV and a frequency between 10 and 60 kHz is generally used. Other voltage ranges and frequency ranges also are possible for the treatment. The desired surface tension of the film is set by means of a targeted setting of the type, the intensity, and the duration of the surface treatment (set, for example, by means of the film forward movement speed).

In preferred configurations, at least one food is arranged in the body and covered by the film. The intermediate space between the body and the food preferably presents a partial vacuum. Particularly, a vacuum is generated in the range between about 100 mbar and 400 mbar. A partial vacuum between about 200 mbar and 300 mbar is even more advantageous.

In advantageous configurations, a gas mixture is present in the intermediate space. The composition of the gas mixture depends on the sealed food given that, for example, meat components require another oxygen content (to maintain the red color of meat) which is not required in foods that do not contain meat (for example, vegetarian dishes or deserts). Particularly, in foods that contain meat, the gas mixture is made up of more than 50% CO₂, and preferably more than 10% N₂, and particularly less than 20%, and preferably less than 10% O₂. Preferably, the percentage of oxygen is further reduced to 7%, 6%, or 5%. The amount of nitrogen is preferably between 15% and 25% and the percentage of carbon dioxide is preferably more than 60 or even 70%. In a specific configuration, a gas mixture of about 75% carbon dioxide and 20% nitrogen and 5% oxygen is used.

Configurations of this type are highly advantageous because by means of the high percentage of inert gases, the reaction and aging of foods is greatly prevented or delayed. An additional advantage is that by means of the percentage of oxygen, a visible discoloration of beef, for example, which tends to adopt a grayish surface when the environment no longer contains oxygen, is prevented. By means of exchanging natural air for the aforementioned gas mixture or one of the aforementioned gas mixtures, the foods can clearly have a longer shelf life, where they can last twice as long, for example. Storability is thereby improved. In preferred configurations, the percentage of oxygen in the gas mixture is greater than 2% and particularly between 3% and 10%.

In advantageous configurations, the film protruding out from the body is cut in a contactless manner. A method referred to as a “out-CUT-method”, in which the film is cut away very close to the body with a blade, can therefore be used, for example. A sealed tray unit that gives a visually appealing impression is also thereby obtained.

Preferably, the adhesive is applied with an adhesive application machine comprising nozzles and/or stationary elements such as, for example, scrapers, and/or rotary elements such as rollers, for example. Preferably, the tray unit is guided by means of, for example, transport rollers particularly with a silicone coating in particular through the adhesive application machine, where the adhesive is applied while the tray unit is being continuously transported.

In preferred improvements, the adhesive is a hot-melt adhesive. In a particularly preferable manner, the adhesive is a polyolefin-based adhering hot-melt adhesive. In a particularly preferable manner, the adhesive has a viscosity greater than 1500 millipascal-seconds at 160° C. The viscosity can reach or exceed about 2200 millipascal-seconds at 160° C., for example.

The method according to the invention is used for sealing at least partially prepared foods, with the foods being positioned on a tray unit and covered with a film. In this regard, an adhesive is applied and a film is adhered thereto in an adhesive region of the tray unit. The surface tension of the film and/or the tray unit is influenced such that the adhesive remains adhered at least predominantly on the film when tearing the film off. Particularly, the adhesive adheres largely and particularly for the most part, and in a particularly preferred manner almost completely or completely, on the film.

With the method according to the invention, partially prepared foods can be advantageously sealed at least partially in a tray unit.

Advantageously, the lower side of the film to be adhered to the tray unit is at least partially surface treated to increase the surface tension of the lower side of the film. Preferably, at least one adhesive is applied to the adhesive region of the tray unit (or the film) by means of rolling, wiping, scraping, and/or spraying.

Preferably, a partial vacuum is generated in an intermediate space between the tray unit and the film and/or an at least partial gas exchange is performed in the intermediate space between the tray unit. A gas exchange of this type should be performed before adhering the film. Preferably, the gas exchange is performed before a vacuum is generated in the intermediate space between the tray unit and the film. Other embodiments can also be conceived.

Particularly, at least one inert gas is preferably supplied to the intermediate space between the tray unit and the film. An inert gas of this type may be or may contain particularly carbon dioxide. Noble gases can also be supplied to a lesser or greater extent as an inert gas.

Additional advantages and features of the present invention can be inferred from the embodiments explained below in reference to the attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of a tray unit and a perspective depiction of two tray units in a cooking appliance;

FIG. 2 shows a highly schematic cross-section through a tray unit;

FIG. 3 shows a plan view of another tray unit;

FIG. 4 shows a schematic section through the tray units according to FIG. 3;

FIG. 5 shows a schematic depiction of a tray unit in an adhesive application machine;

FIG. 6 shows a highly schematic depiction of a tray unit with foods positioned thereon while covering with a film;

FIG. 7 shows a highly schematic depiction of a tray unit with foods arranged thereon, sealed with a film;

FIG. 8 shows a highly schematic depiction of a sealing device for packaging a tray unit with foods arranged thereon in a first position; and

FIG. 9 shows the sealing device according to FIG. 8 in a second position.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a highly schematic plan view of a tray unit 1 which is configured as a rectangular dish and comprises a body 2. The body has a base section 3 and an edge section 4 which, in this case, comprises a total of four edge segments in the longitudinal and transverse borders. The edge section 4 laterally demarcates the base section 3. The base section provides a space sufficient for several foods 30 which can be a component of a part of a meal, for example. It is possible for part of a complete meal to be placed in the tray unit 1. Of these foods, at least some can be partially prepared, i.e. at least partially precooked. All the components of a dish may have the same aggregate state, however, the components in different dishes may also have different aggregate states. In that sense, for example, a first tray unit may also contain deep-frozen foods and another tray unit may only contain foods with refrigerated components.

In the specific embodiment, the tray unit 1 has a tray width 5 of about 17 cm and a tray length 6 of about 33 cm. However, other dimensions are also possible. Particularly, the outer dimensions of the tray unit 1 are adapted to the inner dimensions of a cooking level 102 of a cooking space 101 of a cooking appliance 100. In a particularly preferred manner, two tray units 1 can be located at the same time at the cooking level 102 of the cooking appliance 100. Two or preferably four tray units 1 can therefore be housed at the same time (at two cooking levels). Preferably, the width 105 of the cooking space is about more than twice the width 5 of the tray unit and/or the length 106 of the cooking space is about more than twice the length 6 of a tray unit. The tray units should fill a cooking level 102 of the cooking space 101 as completely as possible, but also still leave a smaller intermediate space with respect to one another and with respect to the cooking space walls. This therefore makes it easier for operator to easily remove the individual tray units. It is particularly advantageous when the intermediate space between and around the tray units is 10% to 40%, and particularly 20% to 40%, of the surface of the cooking level.

The cooking appliance 100 has at least one high-frequency heat source 103 the irradiated frequency of which can be modified in a controlled manner during operation. Preferably, at least two antennas (not depicted) irradiate high-frequency energy and the irradiated frequencies of the high-frequency heat sources 103 and the phases thereof can be modified depending on the measured scattering parameters. Specific regions and/or components or foods 30 in the tray units 1 can therefore be cooked or regenerated in a targeted manner, whereas other foods 30 remain almost or completely free from the influence of the high-frequency heat source 103 due to their composition and/or consistency. By means of housing two or more tray units at the same time, two or more foods arranged on the tray units can be accordingly regenerated and/or fully cooked at the same time. This therefore reduces the number of cooking appliances that are required at the same time when the final preparation of a food for a group of people should be performed at the same time.

It is possible for the cooking appliance 100, in addition to the high-frequency heat source 103, to further have additional heat sources, such as those used in conventional cooking appliances.

FIG. 2 shows a highly schematic cross-section of a tray unit 1. The body 2 of the tray unit 1 has a base section 3 and an edge section 4 in which, in this case, the edge section 4 comprises an oblique region and a horizontal region attached thereto which is oriented essentially parallel to the base section 3. The oblique region has an angle 7 which is, for example, between 10 and 45°. Alternatively, the edge section can also be rounded or angled. It is possible for a decorative edge having, for example, a circumferential pattern, to also be configured in the edge section 4.

FIGS. 3 and 4 show a plan view and a cross-section of a specific embodiment of a tray unit 1. The tray unit 1 is essentially configured as a rectangle and has rounded corners. In this case, the body 2 of the tray unit 1 comprises a large base section 3 occupying an essential part (>50% or >75%) of the surface of the body 2. An edge section 4, which is used for gripping the tray unit 1 and also for holding the film 15, surrounds the base section 3. In this case, there is configured in an independent manner in the embodiment yet another second base section 23 in the body 2 which is used, for example, for housing an independent container 24. A sauce can be housed in the container 24, for example, or other components can be positioned therein.

In this case, the outer edge 9 forms the gripping edge for gripping the tray unit.

The adhesive region 8 is provided on an application surface 18 which, in this case, is formed by means of a raised area 19 in the edge section 4. The raised area 19 with the adhesive region 8 is configured such that it is circumferential to and surrounds the base section 3 in its entirety. A reliable sealing of the foods 30 in the tray unit 1 can thereby be assured.

FIG. 5 shows a highly schematic depiction of an adhesive application machine 20 through which the tray units 1 pass in the through-feed method and are provided with an adhesive coating. To apply the adhesive, nozzles 26 and/or scrapers 27, but preferably a rotary roller 28 can be used, where an adhesive or a sealing material 21 is supplied thereto by means of a storage container 31 with an adhesive store 33. The roller has a relief structure to enable picking up the adhesive better. The transport rollers 32 transporting the tray unit in relation to the roller 28 may have a silicone coating or the like, from which the adhesive that may be located thereon can easily be removed.

FIGS. 6 and 7 show different tray units 1 when the film 15 is adhered on the adhesive region 8 of the tray units 1, in which FIG. 6 depicts the state before sealing the film 15 and FIG. 7 shows the state after generating the partial vacuum and sealing the film 15.

The tray unit 1 depicted in FIG. 6, in which different foods 30 are arranged, is in principle already covered with a film 15. In this case, the film 15 is shown before generating the partial vacuum. The size of the film is adapted to the dimensions of the tray unit 1. The film is made of PET and may particularly have a thickness of 75, 85, or 100 μm.

The partial vacuum is generated in the intermediate space 16 between the film and the body 2 to achieve a longer shelf life by means of less oxygen in the sealed inner space. Furthermore, protection against the sliding of the individual foods 30 in the dish 1 is achieved. Preferably, at least 20% of the volume of air is removed from the intermediate space 16, which is obtained by directly covering the foods 30 with the film 15. Preferably, the vacuum is not generated in at least 5% or at least 10% of the volume of the intermediate space, such that an amount of residual air or particularly a gas mixture remains in the intermediate space 16. By generating the partial vacuum, the pressure the film exerts on the foods 30 is reduced. With an excessive vacuum, the pressure exerted by the film may lead to excessive deformation of the individual foods 30, so the foods or the meal arranged therein may lose quality in terms of their appearance and/or taste. By means of sealing (adhesion), the components or foods 30 are housed in a more protected manner without using a film 15, given that the volume of oxygen is limited in the intermediate space 16. Furthermore, the foods 30 are supported. Overturning and sliding during transport or insertion in the cooking appliance 100 are thereby prevented. Furthermore, an additional protection is achieved because before or after generating the partial vacuum, the air is replaced with a particular gas mixture containing a much smaller amount of oxygen. In this case, it is still important for the packaging machine, before performing sealing and supplying the protective gas, to contain therein a clean atmosphere, given that the exchange of the atmosphere that is predominant up until that time in the packaging machine must be performed.

FIG. 7 shows a tray unit 1 with a film 15, in which the partial vacuum was generated in the intermediate space 16 and air or gas was therefore partially removed from the intermediate space 16. In this case, the sealing material or the adhesive 21 is also illustrated on the surface of the edge section 4 in the adhesive region 8.

Preferably, the gas mixture at least in the intermediate space 16 is modified. This can be performed, for example, by means of supplying inert gas components. The exchange of the gas or gas mixture present in the region of the foods is preferably performed before generating the partial vacuum. To that end, a considerable carbon dioxide component is preferably supplied. Preferably, a gas mixture of this type is supplied, such that with a partial vacuum between about 60% and 85% carbon dioxide, and between 10% and 30% nitrogen, and between 3% and about 10% oxygen are ultimately located in the intermediate space 16. In a specific configuration, a composition of about 75% carbon dioxide and about 20% nitrogen and about 5% oxygen has been proven to be advantageous. In all the configurations, the percentage of oxygen is preferably at least 2%, and particularly between 3% and 8%, or 10%. Too small of an oxygen percentage can lead to unsightly discolorations of the foods (beef), so a visually unappealing impression is generated. The quality of the foods can also be affected.

FIG. 7 shows a blade 29 with which the film section protruding out from the edge of the body 2 can be removed without the blade 29 touching the body 2 of the tray unit 1.

In all cases, the film 15 is first removed before completely cooking or tempering the (partially prepared) foods 30 in the cooking appliance 100.

FIGS. 8 and 9 show a sealing device or sealing machine 200 for sealing a tray unit 1 or the foods 30 arranged thereon. In this regard, the tray unit is suitably positioned in a housing space 206 of the sealing machine 200 or, for example, moves automatically entering the housing space 206. As described above, in the base section 3 of the body 2 of the tray unit 1 there are positioned components or foods 30 to be covered by means of the film 15. The individual foods 30 can together form a part of a meal. Furthermore, the partial vacuum shall be generated in the intermediate space 16 between the film 15 and the foods 30 or the base section 3. To that end, a suction device 202 is used.

The film 15 is supplied by means of a film supplying unit 201 and it is then sized or was already suitably sized beforehand. By means of a blowing device that is not depicted, air or another gas mixture is blown between the tray unit 1 and the film 15, and the film 15 is then lowered onto the tray unit 1 with the foods positioned thereon. After that, the sealing tool 204 of the sealing machine 200 moves downwards and presses the film 15, in this case in the embodiment, onto the adhesive region 8 of the edge section 4. Pressing the film onto the sealing material or the adhesive in the adhesive region 8 can also be performed by means of air pressure or gas pressure.

Previously, the film 15 was heated by means of a tempering device that is not individually depicted, such that it can be more readily expanded.

FIG. 9 shows the sealing machine 200 in a second position in which the sealing tool 204 has almost reached the edge section 4 or the adhesive region 8 of the tray unit 1. The film 15 is thereby placed at least in sections on the adhesive region 8 and on the top parts of the foods 30 and covers same. After the sealing tool 204 has reached the adhesive region 8 and pressed on the film 15, the gas mixture is suctioned out of the housing space 206, and thereby also out of the intermediate space 16 between the film 15 and the tray unit 1, by means of the suction device 202. In this regard, pressure control is performed by means of a pressure gauge 203 which, by means of the supply conduit of the suction device 202, records a measurement for a space inside the intermediate space 16. However, in this regard, the pressure sensor is not located in the intermediate space 16 between the film and the body of the tray unit 1. A partial vacuum is generated, whereby the degree of vacuum also depends on the foods to be packaged or their components. The parameters to be set in the packaging machine (among others, the sealing time, the sealing temperature, the amount of pressure in mbar) are different for each dish. The fragility of the respective food products requires an adapted partial vacuum, for example.

After sealing, the tray units 1 with the components found therein are stored, refrigerated, or even deep-frozen according to requirements. It is important for deep-freezing not to be performed until after sealing to prevent condensation on the film 15. The tray unit 1 can then be arranged inside an outer packaging in which more units can also be housed.

For example, for the exchange of the gas mixture in the intermediate space 16, the inner space of the sealing machine 200 can first be filled with the desired gas mixture, such that the intermediate space 16 is also filled with the desired gas mixture. The partial vacuum can then be generated, such that the volume of the intermediate space 16 is provided with the desired gas mixture.

Generally, a tray unit 1 which is preferably made of magnesium oxide porcelain is provided. The tray unit is particularly made as a dish and preferably has a total length of about 330 mm (+/−15 mm) and a total width of 170 mm (+/−15 mm). The tray unit 1 is particularly suitable for the insertion and transport of the dish packaged with the film in standardized Gastronorm food containers. In preferred configurations, at least one additional container can be positioned in the tray unit. For example, a small dispenser or the like, which is suitable for being filled with a sauce or small side dish components and the like, can be provided. The exact positioning of the container is predefined by means of an independent base section of corresponding size. An independent base section of this type also furthermore provides a defined distance of a container of this type with respect to the edge section 4, which is advantageous for the sealing process.

Preferably, an adhering hot-melt adhesive which provides an adhesive region 8 particularly on a raised area 19 or in the edge section 4 is used. The adhesive region 8 is configured circumferential and continuously and is designed particularly with rounded corners, such that the adhesive as a sealing material may be applied uniformly and with sealing capacity.

The adhesive to be used preferably has a high stability and particularly a viscosity of at least 1500 millipascal-seconds with an application temperature of about 180°. Otherwise, the adhesive is suitable for contact with food products.

It is possible for a decorative border to be provided in the edge section. However, the dish can also be configured without a decorative border.

Preferably, a PET film, which is also particularly suitable for contact with food products, is provided for sealing the foods and/or at least partially prepared meal components. The later preparation of the foods in a cooking appliance entails the removal of the film 15 before preparation. It is thereby assured that upon the removal of the film 15 a large part or especially largest part or complete removal of the adhering hot-melt adhesive can be warranted. Surface residues of the adhesive remaining, for example, on the edge of the dish would constitute a drawback and would be unfavorable during use.

To ensure that the adhesive also peels off as completely as possible when the film is peeled off the tray unit, the film has a correspondingly adapted surface tension of at least 38 mN/m, and particularly 42 or 43 or 44 mN/m.

Particularly, it is highly advantageous if the surface tension of the film used is greater than the surface tension of the dish. For these purposes, at least the lower side of the PET film used is treated, at least in sections, by means of a surface treatment. Particularly, a corona treatment is performed. In this regard, the side facing the food product is subjected to the surface treatment. The dose to be added in the corona treatment is the specific electric energy input in the continuous band of film. Basically, the adhesive behaves in such a way that it always tends towards the higher surface tension. Basically, the sizing of the corona treatment must be adjusted at most to the level required for optimally generating a subsequent adhesion of the food product thus covered on the lower side of the PET film as much as possible.

The adhesive is applied on the tray unit 1 with an adhesive application machine, in which the adhesive application machine can have stationary elements as well as rotary elements, as well as nozzles. In a preferred configuration, a rotary element is considered including a shearing effect to prevent crumb formation. The application of the adhering hot-melt adhesive is preferably performed with a clearly specified amount and temperature.

Preferably, the tool does not touch the tray unit 1 when pressing the film in the sealing process. For example, the pressure can be generated by means of gas pressure, whereby a gas mixture is blown on the film. This prevents the dish from being damaged.

Generally, the invention provides an advantageous tray unit with foods which are arranged in the body and covered by means of a film and an advantageous sealing method.

List of Reference Numbers

-   1 device in the cooking area -   2 tray unit, dish -   2 body -   3 base unit -   4 edge section -   5 width -   6 length -   7 angle -   8 adhesive region -   9 gripping edge, edge -   10 decorative edge -   11 decorative line -   12 decorative width -   14 lower edge section -   15 film -   16 intermediate space -   17 lower side -   18 application surface -   19 raised area -   20 adhesive application machine -   21 sealing material -   22 auxiliary edge -   23 base section -   24 container -   25 lower cup -   26 nozzle -   27 scraper -   28 roller -   29 blade -   30 food, component -   31 container -   32 transport roller -   33 adhesive store -   100 cooking appliance -   101 cooking space -   102 cooking level -   103 high-frequency heat source -   105 width of the cooking space -   106 length of cooking space -   200 sealing machine -   201 film supplying element -   202 suction device -   203 pressure gauge -   204 sealing tool -   206 housing space 

1. A tray unit, particularly a dish, for the packaging, transport, and/or consumption of foods, with a film covering a body, wherein an adhesive for sealing the tray unit is present between the film and the body in an adhesive region, characterized in that the film and the tray unit have a surface tension such that the adhesive adheres at least predominantly on the film upon removing the film, wherein the surface tension in the adhesive region (8) in the film (15) is greater than the surface tension in the adhesive region (8) in the body (2).
 2. The tray unit according to claim 1, wherein the body has at least one base section and at least one edge section and wherein the adhesive region is configured in the edge section.
 3. The tray unit according to claim 1, wherein the edge section is raised at least in the adhesive region with respect to the base section.
 4. The tray unit according to claim 1, wherein there is configured in the body an application surface for the adhesive, which is provided by the adhesive region.
 5. The tray unit according to claim 1, wherein the body (the tray unit) is essentially made of at least a ceramic-type material and wherein the body is particularly made at least partially of magnesium oxide.
 6. The tray unit according to claim 1, wherein the film is made of a plastic material and has a thickness of between 50 μm and 150 μm.
 7. The tray unit according to claim 1, wherein the film is made at least partially of a material such as polyethylene terephthalate.
 8. The tray unit according to claim 1, wherein the lower side of the film is attached to the body and wherein the surface tension in the lower side of the film is modified by means of a surface treatment.
 9. The tray unit according to claim 8, wherein at least a part of the lower side of the film is surface treated by means of a corona treatment.
 10. The tray unit according to claim 8, wherein the type, the intensity, and the duration of the surface treatment depend on the surface tension to be set.
 11. (canceled)
 12. The tray unit according to claim 1, wherein at least one food is arranged in the body and covered by the film and wherein an intermediate space presents a partial vacuum.
 13. The tray unit according to claim 12, wherein a gas mixture which is made up of more than 50% CO₂, more than 10% N₂, and less than 10% O₂ is present in the intermediate space.
 14. The tray unit according to claim 13, wherein the composition of the gas mixture is adapted to the food arranged in the body.
 15. The tray unit according to claim 13, wherein the percentage of O₂ in the gas mixture is greater than 2% or between 3% and 10%.
 16. The tray unit according to claim 1, wherein the protruding film is cut contactless outside the body.
 17. The tray unit according to claim 1, wherein the adhesive is applied by means of an adhesive application machine comprising nozzles and/or stationary elements such as, for example, scrapers, and/or rotary elements such as, for example, rollers.
 18. The tray unit according to claim 1, wherein the adhesive is a hot-melt adhesive.
 19. The tray unit according to claim 18, wherein the adhesive is a polyolefin-based adhering hot-melt adhesive and at 160° C. has a viscosity greater than 1500 millipascal-seconds.
 20. A method for sealing at least partially prepared foods, in which the foods are positioned in a tray unit and covered with a film, characterized in that an adhesive (21) is applied in an adhesive region of the tray unit and a film is adhered thereto and in that a surface tension of the film and/or of the tray unit is influenced such that the adhesive remains adhere at least predominantly on the film when tearing the film off, wherein the surface tension in the adhesive region in the film is greater than the surface tension in the adhesive region in the body.
 21. The method according to claim 20, wherein the lower side of the film being glued to the tray unit is at least partially surface treated to increase the surface tension of the film.
 22. The method according to claim 20, wherein the adhesive is applied in the adhesive region of the tray unit by means of rolling, wiping, scraping, and/or spraying.
 23. The method according to claim 20, wherein the partial vacuum is generated in an intermediate space between the tray unit and the film, and/or wherein at least a partial gas exchange is carried out in the intermediate space.
 24. The method according to claim 23, wherein at least one inert gas is added. 